Grease gun



' Nv. 2o, 1928.

A. T.: SHERE GREASE GUN Filed April 25, 1922 2 Sheets-Sheet 1 Albert I S/z'ere.

Nov. 20, 192.8.

Filed April' 25, 1922 A. T. sHERE GREASE GUN '2 Sheets-Sheet 2 l C' J@ l 9 5,9

/ 5 5o 5 55 16 a? a 54 141 F @www .gaanfed Nav. zo, 1928.'

UNITEu STATES ,PAT-ENT: oFFICfE. f

ALBERT T. SHER'E, OF OAKLAND, CALIFORNIA', .ASSI [(.3`rNO R, BY- MESNE ASSIGNMENTS,

To GAT GUN 'LUBRICATING CORPORATION,

Tron or cALIoRNIA.

Appncaaoniuednpril 25, 1922. serial Nb.. sscyasa.

My invention is an improved grease gun for injecting thick greases into automobile bearings and other parts, which is morerapid and efficient, vand injects its greases with more force than other similar grease guns.

An object of my invention isi to provide' a grease gun which maybe readily loaded with grease and to mount thereon a booster pump grease gun and through a conduit intolthe bearings to be greased.

My invention comprisesa mechanical meth- 4 od as well as the appliance for greasing the bearings; the mechanical method comp-rising the loading of a grease gun by inserting the open mouth in a body of grease, pulling on the plunger or piston rod to suck the grease into the grease gun, locking the most position, then attaching a booster pump to theend of the open cylinder-and releasing the look so that the-piston, due to a resilient medium, forces grease into the booster pump'.

. This pump is then actuated to force the grease through 'a conduit into a hearing, and on eachreturn stroke of the pump, creates a vacuum therein which draws grease into the booster.`

pum'pfrom the grease gun'and at the same time causes the piston in the grease gun to fol'- low the body of grease Without any hand ma.- 0 nipulation.

This is accomplishedby my preferred form of-construction in which a-smooth rodis con nected to the piston and is held by a lookfrom moving inwardy unt-il the lock is released.'

Referring to the annexed drawing in which my invention is illustratedf'and which forms a part o f this specification: Figure 1 is a\side elevation of my grease gun.

grease gun.

Figure 3 is a front end view of my grease section of a modivend of the piston rod 5 extends thou h a central aperture 8 in the rear head 3 an on said piston at its innerf Figure 2 is a longitudinalsection of my GREASE GUN,

end of said rod is a h which the rodis formed a coars nut 11 against l?, the large end of which vengages the inside o large end is'seated in -said head. `The head .2

the head 3 and the extremity 13 of said OF'OAKLANI), CALIFORNIA, A CORPORA- I and wheel 9 by means of; turned. On the piston rod 5is` e thread 10 on which screws a the small endofaconicalspring has a bore 14 extending through oneside and so that the grease may be forced out of the .diametrically almost to the other side thereof in which'reciprocates a plunger 15. An outlet port 16 isprovided in the center of the head 2 leading fromA the interiorof the cylinder 1 to the bore.14. An outlet port 17-is also provided in the. head 2 leading from the closed l' i end of the bore 14 to the outer sideof the head,

which. port is threaded and into which'screws one end of a flexible tube .'18 on the other end of which is a coupling 19. lTheouter end of plunger 15 is pivotally connectedbyapin 20 tov l 'an operating lever21,the forwardendofwhich lever is curvedupwardly and pivotally con- ,the lower ends of which arms-are pivto 'the head 2 at'diametrically by the engagement of thread 10 with nut 11 is drawn rearwardly until it engagessaid'nut A and then the piston is pulled rearwardly further until the spring 1'2is compressed. The head 2 is unscrewed from the cylinder' 1 and the cylinder filled with grease forwardly. of piston 4 while the spring A12' is held compressed. The head 2 is then screwed on the.

forward end of the piston with theplu'nger 15 covering the port 16- and preventing the entrance of grease into the bore 14. The tube 18 is then coupled by the coupling 19 to the bearing or other part to be greased. The lever 21 is then swung upwardly and the vplunger 15' withdrawn upwardly above the port 16.. The spring/12 then forces the piston'4 forwardly which forces grease .through port 16 into bore 14 until said bore is filled with' grease. The lever 21 is then swung downwardly and the plunger 1 5 inwardly which forces the grease out of the bore 1 4'through port 17 'and tube 18 into the bearing orother art. As the'grjease is ejected from the cylin er the 'p1ston rod 5 is turned in the nut to compressthe sprln 12 to'enable said spring to force-the succee ing charges of grease into the bore 14. In the modified form of my inventmn shown in Figure 4, the screw 10, collar 11 and spring 12 are eliminated and a rod 30 and lock 31 are substituted for said screw, while a spring 32 is substituted for the spring 12. The forward end portion 33 of rod 30 is reduced in diameter, forming at its juncture with the main portion of the rod a shoulder 34 at the rear of piston 4, on which reduced forward end portion iits a cbllar 35 against said shoulder, the spring 32 surrounding said reduced forward end portion between said piston and said collar. A nut 36 screws on the forward end of forward end portion 33. The

loclr 31 comprises an arm 37 pivoted at itslower end to lugs 38 on the head 3 and provided with an aperture 39 in its upper end through which aperture extends the rod 30.

The lock arm 37 is swung toward the head 3 to release the rod 30 so that said rod and piston may be drawn back in the cylinder 1 to admit a charge of grease therein. The rod is then pushed forward against the grease while the plunger 15 is down until the spring 32 1s compressed. The spring 32 then forces the rod 30 back slightly which swings the lock arm 37 back until the rod binds against the edges of the aperture 39 and is locked by said lock arm. Upon lifting the plunger 15 the spring 32 forces the piston 4 forwardly and the piston forces the grease through port 16 into bore 14.

It will be noted, referring particularly to Figure 4, that after removal of the booster pump from the end of the cylinder 1, that grease may be drawn into the open cylinder by merely pulling on the rod 30. When the cylinder is filled with grease, the spring 32 becomes compressed between the piston and the rod of the cylinder. The lock 31 may then be locked against the rod 30 to hold the rod from movement toward-s the open end, thus retaining all the grease in the grease gun. The booster pump is then screwed on the open end of the cylinder and attached by a tube,

such as 18, and a coupling 19, to the bearing or the like.

When the lock 31 is released, the spring 32 presses the piston it through the port 16 into the bore 14 of the booster pump, when the plunger is elevated. On the down stroke of the plungerthe grease is forced out through the port 17 at high pressure. On the up strokes a vacuum is created in the bore 14, which sucks grease from the Grease gun. The spring only functions to force the grease into the booster pump in the early stages. After this the suction draws the grease and the atmospheric pressure on the back of the piston causes the piston to follow up the grease as used. This is accomplished by merely releasing the lock 3l so that the rod 30 may travel inwardly and it is not necessary to manually press on the rod 30.. 4

Having described my invention, I claim:

1. In combination, a cylinder adapted to lcontain grease and having a booster pump associated with the front end thereof, a rod extending slidably into the cylinder fromI the rear end thereof and having a piston slidable thereon, an abutment on said rod, a spring cushion bearingon the abutment and on the piston so as to urge y the latter forwardly and a locking means for the rod associated with the rear end of the cylinder, the 4said locking\ means being arranged to allow the rod to be pushed forwardly but to resist rearward motion of the rod. l

2. In combination, a cylinder adapted to contain grease and having a booster pump associated with the front end thereof, a rod eX- tending slidably into the cylinder froml the. rear end thereof and having a piston slidable thereon, an abutment on said rod, ya spring cushion bearing on the abutment and on the piston so as to urge the latter forwardly, and a link pivoted relative to rear end of the cylinder being perforated in the free end and having the rod slidable in said perforation, the link and its perforation being formed to bind the rod against rearward motion.

In testimony whereof I afliX my signature.

. ALBERT T. SHERE.

against the grease, forcing 

